KCNH2 Variant L1027P Detail

We estimate the penetrance of LQTS for KCNH2 L1027P is 8%. We are unaware of any observations of this variant in individuals. L1027P is not present in gnomAD. L1027P has not been functionally characterized. This residue is located in a Non_Hotspot region for LQT2. In silico predictions, functional data (if available), and location in structure are equivalent to observing 0 individuals with LQT2 and 10 unaffected individuals.These data combined with observations of carriers lead us to estimate the LQTS penetrance for KCNQ1 L1027P around 8% (0/10).

In Silico Data

PROVEAN PolyPhen-2 BLAST-PSSM REVEL Penetrance Density (%)
-0.606 0.006 -2 0.569 1
PROVEAN scores less than -2 are considered deleterious. REVEL scores higher than 0.5 or 0.75 are considered likely pathogenic (higher sensitivity with the former cutoff, higher specificity with the latter cutoff). A PolyPhen-2 score of 0.85 or greater is considered likely pathogenic. BLAST-PSSM reflects the evolutionary conservation of residue substitutions, more negative numbers indicate fewer observations of the specific substitution than is expected. Penetrance density is our previously published method to calculate the average LQTS probability density in a shell of residues surrounding a residue of interest (Kroncke et al. 2019).

Reported Carrier Data

PubMed ID Year Carriers Unaffected LQT2 Other Disease
LITERATURE, COHORT, AND GNOMAD: - 0 0 0 -
VARIANT FEATURES ALONE: - 10 10 0 -
Summary totals might not agree with the literature table because of duplicate patients, which were excluded from the total counts. We do not distinguish here between multiple missense codons. Missense variants are combined across degenerate codon substitutions since codon-level data were not consistently available for curation.

L1027P has 31 previously observed neighbors within 15 angstroms

A residue within a folded protein on average has nearest neighbors that fall roughly into two shells: a "nearest" neighbor around 5-6 angstroms and a second shell around 11 angstroms. NOTE: some residues appear multiple times at different distances since the functional KV11.1 channel (protein product of KCNH2/hERG) is a homotetramer and occasionally the same residue from multiple subunits is present within the 15A window. All variants shown in the rightmost column have been observed in at least one individual in the literature or gnomAD.

Neighbor Distance (Angstroms) Variants Observed in Individuals
1027 0 L1027I,
1026 4 P1026R,
1028 4 S1028Del,
1025 5
1029 5 S1029fsX,
1024 7
1030 7 P1030X, P1030L,
1023 8 L1023Del, L1023P,
1031 8 G1031X, G1031fsX, G1031C,
1022 8
1032 8 R1032W, R1032P, R1032Q, R1032X, R1032fsX,
1021 9 S1021N, S1021fsX,
1033 9 R1033W, R1033Q, R1033fsX, R1033X,
1020 10
1034 10 P1034X, P1034fsX,
1019 11
1035 11 R1035W, R1035X, R1035fsX, R1035Q,
1018 11 P1018L, P1018A,
1036 11 G1036Del, G1036D, G1036fsX, G1036X,
1017 12 A1017V, A1017S, A1017T, A1017fsX,
1037 12 D1037N, D1037X, D1037fsX, D1037E, D1037E,
1016 13
1038 13 V1038L, V1038L, V1038X, V1038M, V1038fsX,
1015 13 C1015Y,
1039 13 E1039X,
1014 14 R1014fsX, R1014X,
1040 14
1013 14
1041 14
1012 15 L1012fsX,
1042 15